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.NET Core RSA 指南与增强扩展 RSAExtensions

一. 前言

RSA 作为最常用的非对称加密算法，在我们的实际使用中还是比较常见的，特别是对接支付十有八九都会遇到，或者是其他需要数据安全的业务场景。在 .NET Framework 以及 .NET Core ❤️.0 时，.NET 自带的 RSA 对象仅支持XML标准形式表示的Key，这和其他语言对接其他无疑出现了许多难度，比如 Java 常用的 key 格式是 PKCS#8，JavaScript 一般使用 PKCS#1，万变不离其宗，这些 Key 虽然格式不一样，只要我们将它们导入到 .NET RSA 对象，就都能支持。以前我们主要依赖于一个第三方库 BouncyCastle 来实现这些支持。

前面我基于 BouncyCastle 封装了一个组件来支持 PKCS#1 和 PKCS#8，对于项目低于 .NET Core 3.0 的可以使用下面的解决方案：

现在 .NET Core 3.0 官方增加了对 PKCS#1和 PKCS#8（密码） Key 导入和导出支持，这真的是非常 Nice，详情请看后文分解。

二. RSA Key 认知

这里主要介绍三种常用格式的 Key ，XML、PKCS#1、PKCS#8

XML 私钥：

<RSAKeyValue>
  <Modulus>09Hvw+dbHzi8x+9A1b2S0/128nA61ZyiaazJcDCUety4yHg0cdp5NOnyH35njYR4u2XO5l4GptwzJQfkEzCNoAniofBkb/WMQjvUhJ30eVpa7p/aq+4cgnMYuwYRCOLAB3jpldzIvii1+BOr3oLeT+1blK9f8u3T5liIxV3DBFxEWbnhQWHMgYXpDBIV9cjVhLYZLznefoWZ8N9bVdg1aucgYSWiPbURdfZusyS2fUJgiDLu63KQw8Bhc9cIMnUh6fq2UIBMk1mg/zuKyuMzCM8FX/VvleXJwS11LAgkEhtkOKQXo2xB65+zxPAUl0mKWGKSP9gY8p0+cav4nFCSLQ==</Modulus>
  <Exponent>AQAB</Exponent>
  <P>6ZEU55sugjc/qcPW0u0fSxy5tJYI+8tFsKfw/5AAm4pq2SVfDQHkRODlv5Zr8DnFQz7WN2L7FL6f11qdIjO4/dF9oo5YlD+jlmTOdaZovNLT0w0KGnN3ChFnnyxyNSG33sxlwgUrBppY2W4Sh0rzNQ4VIBhGes6dHxuMg0hWCKM=</P>
  <Q>6ComYZkP5fJrT5tWNSTkb+UGyUwxquXWAgZB8GCkAzrc5t3QgPe+1W0bUSJOVddPX6mxx6yaM+ZMFc5pwdcyxYJ90+T/m2NNviMOC2fHB457OWr4HO0DloYHlWbniXfkOLGrWHshcbIEwbsYWnVYF3mOF2b/xDuDUB57B71Flu8=</Q>
  <DP>k9guL1zfV7W5KrC4btOCF32bX2AJV7kX5/amal6ww8QeVk19mTI1WBQz2c5RjMJEx4gi+PRCkqMHcr388QVkd+X/bMJF97FAz5YHyhkH+15IjzOVzaCBHXJe8TalJFSvmuwvDV1QGuHgk+FFATbENDUx0hsLofjfJC3AB+nl65k=</DP>
  <DQ>v80qvlDUuJUpILBlbSxYaTTeAWmoUtbkkfGXgj5k4aI8o6K3QgTrLKmh+sqLyxFBKvgnvp2TG7N0QkOwTYs7D795spgqr7Y/oQiW7sdCv7RviwUbi9Int7BtDXnhaUmaS1hFBalb/PEkSuUF/p2ZNHOg9yaJwRWlq4gy/jbZChM=</DQ>
  <InverseQ>EydINmQ+aX8+2W7ZxU66P+0XSYsA2M/m7eF0cn5B+N3E2TOYgwunWqjPksyprEtNlP/puf7li/g8G5j3fQ0Xy/KrVwR2emcvCZMqpjzkYhSn9KcVHUVJg/LHb7BDVx/uSZwj9Ok2qDX73PSa91DEsIPiKPQjkVw1QJJ19wlJMiQ=</InverseQ>
  <D>MzwYbp5LYCXtI78vQ4PzO+uXFdUnpfuZHU55+vUFNSKmX3cT2GYr4yyjMBL3ITflrA5YGUis+zdP96kM9cdMumUpuFnZMWuHXY3zPZCnTaMZU5a+4c9afgMw/CvfevK92BDbDzC0LarTOQopDE1DULns6O3ym2QDWTgY/QRM44StLMEaLjNdVhLS3lMZJPrMCtk1k044RStUkL/7yiLMUYtXV+Lpy/08dyHWdXfBcakusKw8EEZZ53skFeR6mkWT51wyKmBFf7D6rfUC+e282i8OGayu79zXvA0UutmUGa1Q9eAP8qsBrc/i++qa/X3JnfBrFyEwQBfQV3kiOM3T0Q==</D>
</RSAKeyValue>

XML 公钥：

<RSAKeyValue>
  <Modulus>o9AYbnx0a9YHjhnaE8E8w1plNsmyqg2tW41sakkoELxRz5PlDAsmc31caXUveSzBY8obp5Jt0hF9EIqY5wzLZQ==</Modulus>
  <Exponent>AQAB</Exponent>
</RSAKeyValue>

PKCS#1 私钥：

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

PKCS#8 私钥：

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

PKCS#1 公钥：

MEgCQQDQViO4nQdwtCq9sOQb99evu/Pjkhk4TpEnn+6uXMz2LaS9xmUtX8lOVCMMlzoSNdu6vPskfUgMGud2hOpcgnLdAgMBAAE=

PKCS#8 公钥：

MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBANFVdaJmHSwAj+5ry0MD98sSZ4nH0hgaUWcUwHF7+ptiX8lrnVGeK4yMlHpS5bgaWFwmdwXRaoAzWBWkEg5yV2ECAwEAAQ==

PKCS#1 和 PKCS#8 的 Key 都是通过 Base64 编码的。

从肉眼很难区分 PKCS#1 和 PKCS#8 私钥，公钥可以根据长度来区分。

XML Key 标准表现形式，展示了 RSA 算法的几个部分，主要是 ：Modulus、Exponent、P、Q、DP、DQ、InverseQ、D。私钥包含所有部分，公钥只包含 Modulus、Exponent 两个部分，所以有了私钥是可以推导出公钥的。

三. Key PEM

PEM 是对 Key 的一种格式化，使之更容易识别。基于上面的普通字符串 Key，它对字符串进行了分割，主要是加了前缀后缀以及每行分割为64个字符。

PKCS#1 公钥

-----BEGIN RSA PUBLIC KEY-----
BASE64 ENCODED DATA
-----END RSA PUBLIC KEY-----

PKCS#8 公钥

-----BEGIN PUBLIC KEY-----
BASE64 ENCODED DATA
-----END PUBLIC KEY-----

PKCS#1 私钥

-----BEGIN RSA PRIVATE KEY-----
BASE64 ENCODED DATA
-----END RSA PRIVATE KEY-----

PKCS#8 私钥

-----BEGIN PRIVATE KEY-----
BASE64 ENCODED DATA
-----END PRIVATE KEY-----

例：PKCS#8 PEM 私钥

-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

四. .NET Core 3.0 RSA 新增功能

.NET Core 3.0 官方增加了对 PKCS#1和 PKCS#8（密码） Key 导入和导出支持，PKCS# 1为默认格式。

方法名 说明
ExportRSAPrivateKey 导出 PKCS# 1 私钥
ExportRSAPublicKey 导出 PKCS# 1 公钥
ExportPkcs8PrivateKey 导出 PKCS# 8 私钥
ExportEncryptedPkcs8PrivateKey 导出 PKCS# 8 加密私钥
ImportRSAPrivateKey 导入 PKCS# 1 私钥
ImportRSAPublicKey 导入 PKCS# 1 公钥
ImportPkcs8PrivateKey 导入 PKCS# 8 私钥
ImportEncryptedPkcs8PrivateKey 导入 PKCS# 8 加密私钥

以 PKCS#1 格式为例，用法如下：

var rsa = RSA.Create();

//导出
Console.WriteLine("RSA PKCS#1 私钥：");
Console.WriteLine(Convert.ToBase64String(rsa.ExportRSAPrivateKey()));
Console.WriteLine("RSA PKCS#1 公钥：");
Console.WriteLine(Convert.ToBase64String(rsa.ExportRSAPublicKey()));

//导入
rsa.ImportRSAPrivateKey(Convert.FromBase64String("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"), out _);
           rsa.ImportRSAPublicKey(Convert.FromBase64String("MIIBCgKCAQEArTLJkbnYqeNXjy1iznnEi8bZjVbP4NabvftKFMdYeCCHfeHXZEvaJFbWcybmWwfj4ZjHH+/hh1RRQVMNgQUD8uXYmdjn7bUAfeyT9ujSulEFzwM2Udm6XtnI5/K2WH9ZHEPqUqNgv0EEthV6Yz+SQYFSYO2xd+TzLMvnW/iCmgb9gQfl85L+cKVvQy2NOod3i+gbTwPM8im1fP43vqVUUE5OD+Hz1Hiwai/RJDC67ZhoSdv1Vor8t9uyg+03fa8gfPj52gFRyHh3y8d/bb1LrJwbXV3cBCLD9aw9bnW3rFRwpP+JuH9VKSpoRA3gwD3vhoz7Y8BBOsC6PSrusAm/lQIDAQAB"), out _);

输出：

image-20191217124058373

使用是非常简单的，如果使用PKCS#8，更改一下上面示例代码的方法名就行了。

使用这些API需要的项目使用的目标框架满足：

平台名称 支持版本号
.NET Core >=3.0
.NET Standard >=2.1

五. RSAExtensions 介绍

从上面可以看出，.NET Core 已经原生支持了PKCS#1和PKCS#8 ，这对于和其他语言对接是十分方便的，但是美中不足的是没有对 PEM 支持，以及对 XML 格式的支持。

RSAExtensions 项目就是为了弥补上面这个缺点且支持RSA大数据加密，基于 RSA 对象来添加的扩展方法，使用同样也是非常方便的。

开源地址： https://github.com/stulzq/RSAExtensions （希望来个Star支持一下）

Nuget： https://www.nuget.org/packages/RSAExtensions

RSAExtensions 功能如下：

  • 提供以前Framework有的XML格式的密钥导入和导出
  • 提供对PKCS#1、PKCS#8 PEM格式导入和导出支持
  • 提供对PKCS#1、PKCS#8、XML格式的统一导入和导出
  • 提供对大数据分段加密的支持

增加的API：

方法名 说明
ExportPrivateKey 统一导出私钥，支持 PKCS#1、PKCS#8、XML以及PEM格式化
ExportPublicKey 统一导出公钥，支持 PKCS#1、PKCS#8、XML以及PEM格式化
ImportPrivateKey 统一导入私钥，支持 PKCS#1、PKCS#8、XML以及PEM
ImportPublicKey 统一导入公钥，支持 PKCS#1、PKCS#8、XML以及PEM
ImportXmlPrivateKey 导入XML私钥
ImportXmlPublicKey 导入XML公钥
ImportPkcs8PublicKey 导入Pkcs8公钥
ExportXmlPrivateKey 导出XML私钥
ExportXmlPublicKey 导出XML公钥
ExportPkcs8PublicKey 导出Pkcs8公钥
EncryptBigData 大数据分段加密
DecryptBigData 大数据分段解密

六. RSAExtensions 使用

using System.Security.Cryptography;

var rsa=RSA.Create();

导出

PKCS#1 导出

rsa.ExportPrivateKey(RSAKeyType.Pkcs1); //私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs1); // 公钥

私钥输出：

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

PKCS#1 PEM 导出

rsa.ExportPrivateKey(RSAKeyType.Pkcs1,true);//私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs1,true);//公钥

私钥输出：

-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

PKCS#8 导出

rsa.ExportPrivateKey(RSAKeyType.Pkcs8);//私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs8);//公钥

私钥输出：

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

PKCS#8 PEM导出

rsa.ExportPrivateKey(RSAKeyType.Pkcs8, true);//私钥
rsa.ExportPublicKey(RSAKeyType.Pkcs8, true);//公钥

私钥输出：

-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

XML 导出

rsa.ExportPrivateKey(RSAKeyType.Xml);//私钥
rsa.ExportPublicKey(RSAKeyType.Xml);//公钥

私钥输出：

<RSAKeyValue>
  <Modulus>09Hvw+dbHzi8x+9A1b2S0/128nA61ZyiaazJcDCUety4yHg0cdp5NOnyH35njYR4u2XO5l4GptwzJQfkEzCNoAniofBkb/WMQjvUhJ30eVpa7p/aq+4cgnMYuwYRCOLAB3jpldzIvii1+BOr3oLeT+1blK9f8u3T5liIxV3DBFxEWbnhQWHMgYXpDBIV9cjVhLYZLznefoWZ8N9bVdg1aucgYSWiPbURdfZusyS2fUJgiDLu63KQw8Bhc9cIMnUh6fq2UIBMk1mg/zuKyuMzCM8FX/VvleXJwS11LAgkEhtkOKQXo2xB65+zxPAUl0mKWGKSP9gY8p0+cav4nFCSLQ==</Modulus>
  <Exponent>AQAB</Exponent>
  <P>6ZEU55sugjc/qcPW0u0fSxy5tJYI+8tFsKfw/5AAm4pq2SVfDQHkRODlv5Zr8DnFQz7WN2L7FL6f11qdIjO4/dF9oo5YlD+jlmTOdaZovNLT0w0KGnN3ChFnnyxyNSG33sxlwgUrBppY2W4Sh0rzNQ4VIBhGes6dHxuMg0hWCKM=</P>
  <Q>6ComYZkP5fJrT5tWNSTkb+UGyUwxquXWAgZB8GCkAzrc5t3QgPe+1W0bUSJOVddPX6mxx6yaM+ZMFc5pwdcyxYJ90+T/m2NNviMOC2fHB457OWr4HO0DloYHlWbniXfkOLGrWHshcbIEwbsYWnVYF3mOF2b/xDuDUB57B71Flu8=</Q>
  <DP>k9guL1zfV7W5KrC4btOCF32bX2AJV7kX5/amal6ww8QeVk19mTI1WBQz2c5RjMJEx4gi+PRCkqMHcr388QVkd+X/bMJF97FAz5YHyhkH+15IjzOVzaCBHXJe8TalJFSvmuwvDV1QGuHgk+FFATbENDUx0hsLofjfJC3AB+nl65k=</DP>
  <DQ>v80qvlDUuJUpILBlbSxYaTTeAWmoUtbkkfGXgj5k4aI8o6K3QgTrLKmh+sqLyxFBKvgnvp2TG7N0QkOwTYs7D795spgqr7Y/oQiW7sdCv7RviwUbi9Int7BtDXnhaUmaS1hFBalb/PEkSuUF/p2ZNHOg9yaJwRWlq4gy/jbZChM=</DQ>
  <InverseQ>EydINmQ+aX8+2W7ZxU66P+0XSYsA2M/m7eF0cn5B+N3E2TOYgwunWqjPksyprEtNlP/puf7li/g8G5j3fQ0Xy/KrVwR2emcvCZMqpjzkYhSn9KcVHUVJg/LHb7BDVx/uSZwj9Ok2qDX73PSa91DEsIPiKPQjkVw1QJJ19wlJMiQ=</InverseQ>
  <D>MzwYbp5LYCXtI78vQ4PzO+uXFdUnpfuZHU55+vUFNSKmX3cT2GYr4yyjMBL3ITflrA5YGUis+zdP96kM9cdMumUpuFnZMWuHXY3zPZCnTaMZU5a+4c9afgMw/CvfevK92BDbDzC0LarTOQopDE1DULns6O3ym2QDWTgY/QRM44StLMEaLjNdVhLS3lMZJPrMCtk1k044RStUkL/7yiLMUYtXV+Lpy/08dyHWdXfBcakusKw8EEZZ53skFeR6mkWT51wyKmBFf7D6rfUC+e282i8OGayu79zXvA0UutmUGa1Q9eAP8qsBrc/i++qa/X3JnfBrFyEwQBfQV3kiOM3T0Q==</D>
</RSAKeyValue>

导入

PKCS#1 导入

rsa.ImportPrivateKey(RSAKeyType.Pkcs1, "<privateKey>"); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs1, "<publicKey>"); //公钥

PKCS#1 PEM 导入

rsa.ImportPrivateKey(RSAKeyType.Pkcs1, "<privateKey>",true); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs1, "<publicKey>",true); //公钥

PKCS#8 导入

rsa.ImportPrivateKey(RSAKeyType.Pkcs8, "<privateKey>"); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs8, "<publicKey>"); //公钥

PKCS#8 PEM 导入

rsa.ImportPrivateKey(RSAKeyType.Pkcs8, "<privateKey>",true); //私钥
rsa.ImportPublicKey(RSAKeyType.Pkcs8, "<publicKey>",true); //公钥

XML 导入

rsa.ImportPrivateKey(RSAKeyType.Xml, "<privateKey>"); //私钥
rsa.ImportPublicKey(RSAKeyType.Xml, "<publicKey>"); //公钥

七. RSAExtensions 大数据分段加密

下文所说的“长度”均为字节长度。

RSA算法的加密数据长度根据不同的填充算法，一般最多支持 Key 模长( modulus )相等长度的数据，如果超过这个长度将会需要对数据进行拆分加密。

.NET Core 不支持 RSA_NO_PADDING 填充

Key 模长=KeySize/8

以下是我测试整理出来的 .NET Core 支持的填充算法的支持的加密数据长度：

填充算法 最小 KeySize 最大加密数据长度
Pkcs1 512 模长-11
OaepSHA1 512 模长-42
OaepSHA256 1024 模长-66
OaepSHA384 1024 模长-98
OaepSHA512 2048 模长-130

RSAExtensions 已经封装好了分段加密，无需关心数据长度和模长的关系，使用方法如下：

var encrypt = rsa.EncryptBigData(data, <填充算法>); //加密
var decrypt = rsa.DecryptBigData(encrypt, <填充算法>); //解密

八. 数据加密与解密

加密与解密主要使用两个方法：Encrypt 计算密文，Decrypt 根据密文解密

例：

var rsa = RSA.Create();
var data = "aaa";
var encrypt = rsa.Encrypt(Encoding.UTF8.GetBytes(data),RSAEncryptionPadding.Pkcs1); //加密
rsa.Decrypt(encrypt, RSAEncryptionPadding.Pkcs1); //解密

.NET 中的RSA仅支持 公钥加密，私钥解密

九. 数据签名与验签

签名与验签使用两个方法：SignData 计算数据签名，VerifyData 验证数据签名。使用私钥签名，公钥验签。

例：

var rsa = RSA.Create();
var data = "aaa";
var sign = rsa.SignData(Encoding.UTF8.GetBytes(data), HashAlgorithmName.SHA1, RSASignaturePadding.Pkcs1); //签名
rsa.VerifyData(Encoding.UTF8.GetBytes(data), sign, HashAlgorithmName.SHA1, RSASignaturePadding.Pkcs1); //验签

十. 使用技巧

1.密钥转换

从一种格式导入，使用另一种格式导出。

例：私钥PKCS#1转换为PKCS#8

var rsa = RSA.Create();
rsa.ImportRSAPrivateKey(<PKCS#1私钥>,out _); //导入PKCS#1私钥
rsa.ExportPkcs8PrivateKey() //导出为PKCS#8私钥

2.私钥导出公钥

var rsa = RSA.Create();
rsa.ImportRSAPrivateKey(<PKCS#1私钥>,out _); //导入PKCS#1私钥
rsa.ExportRSAPublicKey(); //导出私钥

3.PKCS#8 加密私钥去密码

var rsa = RSA.Create();
rsa.ImportEncryptedPkcs8PrivateKey(password,paivateKey); //导入加密私钥
rsa.ExportPkcs8PrivateKey(); //导出无密码私钥

4.通过命令行生成转换Key

十一. 常见错误

报错代码：var rsa = RSA.Create(256);

异常：

Unhandled exception. System.Security.Cryptography.CryptographicException: Specified key is not a valid size for this algorithm.

解决：KeySize不够，增加 KeySize大小

报错代码：rsa.Encrypt

异常：

Unhandled exception. Internal.Cryptography.CryptoThrowHelper+WindowsCryptographicException: 参数错误。

解决：KeySize不够，增加 KeySize大小或者数据过长，需要选择大数据分段加密

报错代码：rsa.Encrypt

异常：

Unhandled exception. System.Security.Cryptography.CryptographicException: The message exceeds the maximum allowable length for the chosen options (53).

解决：数据过长，需要选择大数据分段加密

报错代码：rsa.Importxxxx导入Key

异常：

Unhandled exception. System.Security.Cryptography.CryptographicException: ASN1 corrupted data.

解决：导入方法与Key格式不匹配，更换导入方法

十二. 结束

RSAExtensions 开源地址： https://github.com/stulzq/RSAExtensions （希望来个Star支持一下）

参考文章：

posted @ 2019-12-17 13:21  晓晨Master  阅读(12635)  评论(33)  编辑  收藏  举报